The present invention relates to methods of stimulating tyrosinase expression or melanin synthesis in the skin or hair of a mammal comprising topically applying to the skin or hair of the mammal a composition comprising at least one nonpolar grape seed extract (hereafter “nonpolar GSE”), for example, a nonpolar GSE obtained using hexane as an extraction solvent by itself, or as an extraction solvent after extraction with acetone (hereafter “hexane subfraction”), and a cosmetically suitable vehicle.
A lack of gray or graying hair is generally associated with a youthful or aesthetically pleasing appearance. A sun tanned skin is also generally associated with a youthful or aesthetically pleasing appearance. However, there are disadvantages associated with current methods for covering gray or graying hair and for increasing a tanned appearance.
For example, typically, one will use a temporary or permanent hair dye to mask or cover the gray hair. These dyes, however, can be harsh, dry or damage hair, and typically fade and grow out over time, leading to dull hair and gray hair roots. Similarly, a tan appearance is typically achieved by either repeated or prolonged exposure of the skin to— ultraviolet rays in sunlight or to chemical and natural stains. In recent years, prolonged exposure to ultra-violet rays, both natural and artificial, has been associated with life-threatening disorders such as melanoma or various other forms of skin cancer. Prolonged exposure to ultra-violet rays is also associated with undesirable characteristics such as wrinkled or prematurely aged skin. Chemical and natural stains for the skin may result in a non-natural skin color, may have an unpleasant odor, usually only provide a short duration of tan appearance, and are generally difficult to apply.